Rubber hydrochloride compositions



Patented Jan. 7-, 1947 RUBBER HYDROCHLORIDE COMPOSITIONS Winfield Scott,Akron, Ohio, assignor to Wingfoot Corporation, Wilmington, Deb, acorporation of Delaware No Drawing. Application August 8, 1942. SerialNo. 454,123

1 V This invention relates to the stabilization of rubber hydrohalidesagainst deterioration by the action of light, either direct or diffused.More particularly, it is'directed to the use of nonvolaof thisinventionmay be used to stabilize the film and to elasticize it.

2 Claims. (Cl. 260-735) The stabilizers or photochemical inhibitors of vthe present invention are amides formed by the vention:

In the foregoing formulae, R is hydrogen, alkyl,

trates the formation of the amides of this in- 2 alicyclic or a'ralkyl.alicyclic substituent as in morpholine derivatives, or other equivalentneutral groups. R1 is any of the same substituents as R though it is notnectile, basic, photochemical inhibitors which may 5 essarily the sameas R in the same molecule. R2 be used in rubber hydrochloridecompositions represents a straight or branched aliphatic a d wh h m vthe sta l ty f t e ru radical as found in the fatty acids. This radicalhydrochloride regardless of whether the'rubber may contain substituentssuch as hydroxyl as hydrochloride contains an elasticizing material orwould be the case in ricinolelc acid. R2 may be is.unelasticlzed. l0unsaturated as in oleic acid. It can be readily It is known to thosefamiliar with the art that seen that the number of acids that maybe usedrubber hydrohalides under certain conditions, is considerable withoutdeparting from the spirit especially upon exposure to sunlighdeteriorate of the invention. The following examples illusrelativelyrapidly, and their useful life is but a trate the preparation of suchamides: fraction of what it would be under different con- E l 1 ditionsof exposure. The purpose of the present ramp invention is to provide anew class of stabilizers Fifty-seven and four. tenths parts of' stearicwhich'are useful in both prevention of deteacid and 37.8 parts oftetraethylene pentamine rioration and in the plasticization orelasticizawere mixed and heated together in a suitable re- Y tion ofrubber hydrohalide films. actor equipped with a condenser and thermome-The stabilizers of this invention have extremely ter. At a temperatureof 150 C. reaction is oblow vapor pressures so that they can be classedvious. The temperature is raised to about 200 C. as nonvolatile. They,therefore, remain in the and maintained until no more water is obtainedrubber hydrochloride film and protect it for a as a distillate. Thisrequires abouttwo-hours. longer time than other stabilizers which aremore A quantitative yield of a waxy solid is obtained. voltaile. It isbelieved to have the following formula: h The elasticizers orplasticizers which have pre- H,N (CH, CHPNH PCHFCHPNH-C viouslybeen usedfor increasing the tear strength Ea: Z z and to give a softer feel torubber hydrochloride amp e films have usually been esters of higherfatty 3 The amide formed form equal molar proporacids, such as butylstearate, etc. The stabilizers tions of abietic acid and tetraethylenepentamine of this invention are compatible with such elaswas prepared byheating together methyl abietate ticizers and themselves have a definiteelasticizand tetraethylene pentamine with the removal ing action whichpermits the use of less of the of methanol. Sixty-three and three tenthsgrams usual elasticizer or its omission altogether in of methyl abietateand 37.8 of tetraethylene pentorder to give a film which is elasticizedto the eX- amine were heatedfor four hours at 200-215" C. tent desired.A few per cent of one of the staor until no more methanol was given offor no bllizers of this invention, as for example 2 to 8 per further lossin weight of the reaction mixture cent, will give a marked improvementin the stawas observed. The final product was a soft, ambility of thefilm. Up to 15 per cent of an amide 40 ber-colored resin.

Example 3 Capric acid and tetraethylene pentamine readr ily react toform an amide by heating together the two materials. Fifty-one and sixtenths parts of capric acid and 56.7'parts of tetraethylene' pentaminewere heated together at -200 for one and a half hours, when 5.1 g. ofwater was condensed. The product is a, viscous liquid that Y depositssome crystals on standing. A quantitative yield was obtained.

Example 4 Two molar proportions of capric acid react with It may also bea heterocyc lic I base. This material was prepared by heating 'together,as in the examples above, 103.2 parts of capric acid and 56.7 parts oftetraethylene pentamine. At 200 C. the calculated amount of water wasformed, and the yield of diamide was theoretical. The product is ayellowish, crystalline mush.

' Example 5 The amide from lauric acid and triethylene tetramine wasprepared by heating these two materials together with the removal ofwater.

Heating was continued for one and a half hours at 190-198 C. The productwas made from 50.0 g. of lauric acid and 36.5 g. of triethylenetetramine and was obtained as a light-colored, lowmelting solid inquantitative yield.

Example 6 Although ethylene amines have been disclosed specifically, itis possible to use propylene amines or mixed ethylene and propleneamines, etc. Such amines may be made from a mixture of alkylene halidesand a mixture of ammonia and primary aliphatic amines. It is notnecessary that all amine groups be unsubstituted as in the case, forexample, of tetraethylene pentamine. Some must be unsubstituted forreaction with acids to form amides.

As illustrative of this invention, there was prepared a benzene cement,containing rubber hydrochloride and butyl stearate in an amount equal to5 per cent of the weight of the rubber hydrochloride to which the amidesprepared according to the above examples were added in an amount equalto 5 per cent of the weight of the rubber hydrochloride. Films cast fromthis cement all had materially longer life than the similarly preparedfilm which contained no stabilizer.

What I claim is;

1. A rubber hydrochloride film which contains as a stabilizer an amideof a monocarboxylic aliphatic acid with a polyalkylene polyamine.

2. A rubber hydrochloride film which contains as a stabilizer an amideof a monocarboxylic aliphatic acid with a polyethylene polyamine.

- WINFIELD SCOTT.

